U.S. Pat. No. 5,719,731 entitled "Locking Device for Preventing Unauthorized Access to Floppy Disk Drives of Personal Computers" to Thomas J. Harmon disclosed a locking device inserted within the disk drive of a personal computer including a pair of pivoted plates retained in their expanded locking position by a key-operated lock carried by the pivoted plates. For unlocking the floppy disk drive as locked by such a conventional locking device, a key should be carried and provided for unlocking use, causing inconvenience for the user since the key may be lost or forgotten to carry.
The present inventor has found the drawback of the conventional locking device for disk drive and invented the present combination lock means for floppy disk drive.